Technical Abstract:
Functional genetics implies a robust understanding of the characteristics of a gene, including where, when, and how it behaves in an organism. This level of investigation has been mostly limited to model organisms such as yeast or Drosophila. However, current technology and bioinformatics allow for studies on non-model organisms such as the tarnished plant bug, Lygus lineolaris. As a first step in identifying functional genes, a cDNA library was prepared from a laboratory-reared colony of L. lineolaris male nymphs. A small number of sequences were obtained and compared to known genes. Sequences that appeared to have known functions or close homologues have been targeted for further study. Three sequences appeared to encode polygalacturonase (PG) enzymes, and cDNAs were cloned in their entirety by Rapid Amplification of cDNA Ends (RACE). Other sequences of interest include actins, tubulins, ribosomal subunits, proteinases, and cuticle genes. To identify expression profiles for these genes, as related to developmental stage and sex of the insect, total RNA samples were collected from eggs at 3 and 8 days of development, 2nd instar nymphs, 5th instar nymphs (identifiable as either male or female) and adults, male and female. Equal quantities of total RNA were reverse transcribed and used for semiquantitative PCR. Several genes, including the PGs, were expressed with stage- and sex-specificity. Constitutively expressed genes were identified and will be useful as standards.